#include <bits/stdc++.h>
using namespace std;
int cal1(int k) {
  int ans = 0;
  while (k > 0) {
    ans++;
    k = k / 10;
  }
  return ans;
}

int cal1(string s) { return s.size(); }

int cal3(int k) { return int(log10(k) + 1); }

int main() {
  cout << cal3(10000);
  return 0;
}